The document describes the SIPv6 Test Program run by the University of New Hampshire InterOperability Lab (UNH-IOL) to test Session Initiation Protocol (SIP) implementations over IPv6 networks. The UNH-IOL has developed a comprehensive test plan with over 150 test cases, an automated test tool based on 500 scripts, and a secure IPv6 test network to conduct interoperability testing between SIP implementations from different vendors. Vendors can test their implementations both remotely over a VPN or on-site at the UNH-IOL facilities.